A controlled study of recombinant human granulocyte colony-stimulating factor in elderly patients after treatment for acute myelogenous leukemia. AML Cooperative Study Group.

BACKGROUND: Intensive chemotherapy for acute myelogenous leukemia (AML) continues to yield low rates of complete remission and survival among patients over the age of 65 years. Infection-related mortality is particularly high among these patients during the period of neutropenia that follows chemotherapy. We determined the effect of lenograstim (glycosylated recombinant human granulocyte colony-stimulating factor) on mortality at eight weeks (the main end point) and the rate of complete remission among patients with AML who were 65 years old or older.

METHODS: After induction chemotherapy with daunorubicin (45 mg per square meter of body-surface area per day for 4 days) and cytarabine arabinoside (200 mg per square meter per day for 7 days), 173 patients with newly diagnosed AML were randomly assigned on day 8 to receive either lenograstim (5 micrograms per kilogram of body weight per day) or placebo, starting on day 9, until there was neutrophil recovery or a treatment failure, or for a maximum of 28 days. Salvage chemotherapy was also followed by lenograstim or placebo. Patients with a complete remission received two consolidation courses of chemotherapy without lenograstim or placebo.

RESULTS: The mortality rate at eight weeks was similar in the lenograstim and placebo groups (23 and 27 percent, respectively; P = 0.60), as was the incidence of severe infections. The median duration of neutropenia (absolute neutrophil count < or = 1000 per cubic millimeter) was shorter in the lenograstim group (21 days, as compared with 27 days in the placebo group; P < 0.001). Eight percent of the patients in both groups had regrowth of AML cells. The rate of complete remission was significantly higher in the lenograstim group (70 percent, as compared with 47 percent in the placebo group; P = 0.002). Overall survival, however, was similar in the two groups (P = 0.76).

CONCLUSIONS: The administration of lenograstim after chemotherapy for AML did not decrease the mortality rate at eight weeks among patients over the age of 65 years. The patients who received lenograstim had a significantly higher rate of complete remission than those who received placebo. Nevertheless, the overall survival in the two groups did not differ significantly.